Many conventional warming therapy devices (e.g., incubators, warmers, etc.) include some type of air circulation system. Typically, the air circulation system is used for moving heated, humidified air into and out of a space surrounding a patient. For example, in a typical ‘closed care’ environment the patient may be covered by a hood or other member which assists in maintaining a desired temperature and humidity around the patient. In such a setting, air circulation systems are used to move heated, humidified air across the patient, in order to maintain a desired patient temperature and reduce the water loss.
For example, U.S. Pat. No. 5,935,055, the disclosure of which is hereby incorporated by reference in this application, as if fully set forth herein, shows a conventional warming therapy device including a lying surface 1 for a patient, and a housing 8 (i.e., hood) for surrounding the patient. Also included are a fan 4 and electric drive motor 5 for rotating the fan. A circular air heater 6 surrounds the fan 4 and operates to heat the air inside the housing 8. In particular, heated air is blown by the fan 4 to first and second nozzles 11 (as shown by the directional arrows in FIG. 2), where it is transmitted into the upper part of the housing 8 through parallel slots 7 which run along the two long sides of the housing. Exhaust slots 9 are provided along the two short sides of the housing 8 for collecting the air transmitted to the upper portion of the housing, and for returning such air to the area around the fan 4.
U.S. Pat. No. 5,730,355, the disclosure of which is hereby incorporated by reference into this application, discusses an incubator in which an air curtain is formed when one of first and second access doors 12, 20 of a hood 10 are opened, in order to maintain the temperature and environment within the hood. In particular, the incubator includes openings 24, 26 through which air passes into the area of the hood 10. When one of the access doors 12, 20 is opened, the temperature of a heater 32, and the speed of a fan 36, are increased to create an air curtain across the open access door, and compensate for temperature losses through the open access door.
U.S. Pat. No. 6,270,452, the disclosure of which is hereby incorporated by reference into this application, discusses an air circulation system for a warming therapy device. The warming therapy device 1 includes a head end 5a, a foot end 5b, and lateral sides 5c, 5d. The lateral sides 5c, 5d and the foot end 5b include slots 37 from which air emanates forming air curtains 20-22 and 23-25. The head end 5a includes an intake 63 (i.e., air return nozzle) which collects the air emanating from the slots 37 and returns it to an air circulation system.
Finally, US Pat. Pub. No. 2008/0234538, the disclosure of which is hereby incorporated by reference into this application, discusses an air circulation system for a warming therapy device. The warming therapy device 1 includes two lengthwise sides 2, a head side 3, and a foot side 4. The lengthwise sides 2 and the foot side 4 include air supply means 7,8, respectively. The head side 3 includes a front wall 10 in which is disposed an exhaust means 9 (i.e., air return). In operation, air which exits the lengthwise and foot side air supply means 7, 8 is blown toward the exhaust means 9, where it is collected and re-circulated.
However, air circulation systems of conventional warming therapy devices (such as the ones discussed above) often times cannot maintain a desired humidity level in the microenvironment around the patient if an access portal (e.g., hand port, hood) is opened. Additionally, such conventional devices are often difficult to clean, due to the way in which they are integrated into the warming therapy devices. For example, the air flow ducts for conventional air circulation systems are often built into the base of the respective warming therapy device, and thus are difficult (and sometimes impossible) to disassemble and clean. Because one of the objectives of a warming therapy device is to create a sterile and hygienically sound environment for the patient, an air circulation system which may be easily disassembled and cleaned is highly desirable.
Accordingly, there is presently a need for a warming therapy device that includes an air circulation system which can maintain a desired humidity in open care configurations (e.g., where a hand port or the hood is open) may be easily disassembled and cleaned, but which also maintains a high rate of air flow through the device.